Core Design Patterns(1) Decorator 装饰模式

VS 2008

当我们需要给一个已有的对象动态的附加状态或行为时，使用装饰模式。
装饰模式的要点是：装饰类实现了最初的被装饰类，并且包含了被装饰类的一个实例

1. 模式静态类图

2. 应用

从一只可以写的Pen开始
把它装饰成有颜色的笔、粗线的笔，甚至可以是有颜色且粗线的笔

IWritable

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace DesignPattern.Decorator.BLL {

interface IWritable {

void Write();

}

Pen

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace DesignPattern.Decorator.BLL {

class Pen : IWritable {

IWritable Members

}

ColoredPen

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace DesignPattern.Decorator.BLL {

class ColoredPen : IWritable {

IWritable component = null;

string color = string.Empty;

public ColoredPen(IWritable component, string color) {

this.component = component;

this.color = color;

}

IWritable Members

public void SetColor(string color) {

this.color = color;

}

BoldPen

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace DesignPattern.Decorator.BLL {

class BoldPen : IWritable {

IWritable component = null;

int borderWidth = 0;

public BoldPen(IWritable component, int borderWidth) {

this.component = component;

this.borderWidth = borderWidth;

}

IWritable Members

public void SetBorderWidth(int borderWidth) {

this.borderWidth = borderWidth;

}

Client

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using DesignPattern.Decorator.BLL;

namespace DesignPattern.Decorator {

class Program {

static void Main(string[] args) {

IWritable p = new Pen();

p.Write();

Console.WriteLine();

ColoredPen coloredPen = new ColoredPen(p, "red");

coloredPen.Write();

Console.WriteLine();

BoldPen boldPen = new BoldPen(p, 2);

boldPen.Write();

Console.WriteLine();

BoldPen coloredAndBoldPen = new BoldPen(coloredPen, 4);

coloredAndBoldPen.Write();

}

posted on 2008-02-24 22:05 Tristan(GuoZhijian) 阅读(221) 评论(1) 编辑收藏所属分类: Design Pattern

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